Wikia

“	I'd suggest making a note of which doors you go through as you explore.”
	— Daroach • Kirby Mass Attack

Doors are portals which get Kirby from one area to another. In most cases, they are a black arch with stars at the top of them. In Kirby's Adventure, doors do not have any stars around it except for the final door in each level. In Kirby & the Amazing Mirror, they are replaced by Mirror Doors, which act exactly like a regular door, but looks like a mirror and can possibly lead Kirby to different worlds. An enemy, Mirra, is sometimes seen around a Mirror Door, and must be defeated before Kirby can enter. Sometimes, both types of doors are hidden by Star Blocks, and other times Kirby needs to pound a stake to break down walls and reveal doors.

In Kirby: Canvas Curse, doors are slightly bigger relative to Kirby and have more stars. The final door is replaced by a rainbow canvas that warps Kirby out of the dimension upon contact. A door is also drawn in Paint Panic.

In most games, the player must press up to enter a door, but in Kirby: Canvas Curse and Kirby Mass Attack, Kirby enters the door automatically.

Usually, certain doors look different than others in the same game, which often denotes a different type of area. For example, in Return to Dreamland, doors with orange stars above them lead to secret rooms or even different routes that contain more bonuses than the regular path. Doors simply leading through the levels have the traditional yellow star. Additionally, the final door in each level that serves as its exit looks different; it is much larger with a rainbow aura. Interestingly, Kirby can carry items, like Keys, through doors.